I did the bolt together frame and used a 3/4 in plywood sheet. I screwed the plywood down every 6 inches. I tried to countersink them the best I could. Some of the screws didn’t go in far. Was this frame setup for a sheet of the foam board or is the material to be cut placed directly on this board. I am concerned that the router bit will hit a screw. How do I fix this?
You should place a spoilboard over you frame backboard and either clampnit in place or screw it along the edges where you won’t be cutting. Something cheap and soft is good (not a hardwood). Many are using rigid foam insulation as the spoilboard
Bar has had no issues with going through screw heads. The only downside to going though a screw is it my dull the bit. Again Bar has said he has gone right through them without indecent. He is screwing around the outside edges.